He describes saltationism, which is what I think Alan is referring to, extremely exaggerates the evolutionary role of saltations, considering these to be the main factor of speciation and macroevolution.

A "monkeys & typewriters" program would simply guess strings independently until it got a match, which would take a very long time; such a "monkeys" program could be regarded as a model of saltationism, but not selective evolution.

Running through the various evolutionary options -- Lamarckism (the inheritance of acquired characteristics), saltationism (evolution by massive jumps), and others -- Dawkins points out that either they are false (Lamarckism) or they fail to account for adaptive complexity (saltationism).